The present invention relates to an electric blower and an electric cleaning device using the same. More specifically, the present invention relates to an improvement in electric blowers that is suitable for use in electric cleaning devices that circulate exhaust air from the electric blower to the suction tool via a hose and a pipe.
In order to cool their heat-generating motor drive section, standard electric blowers used in electric cleaning devices and the like have taken all the exhaust air discharged radially from a centrifugal fan and redirected it in the direction of the motor shaft by guiding the air along a diffuser and the inner perimeter surface of a fan cover. The air passes through a diffuser return path and flows from an air passage formed on a motor frame through a bracket to cool the motor drive section. The air is then discharged outside through a bracket discharge opening.
In standard cleaning devices that are moved along floors, all the exhaust air from an electric blower mounted in the main cleaning device unit is discharged outside through a discharge opening in the back surface of the main unit or the like.
The debris sucked in with air through a floor suction tool or the like is passed through a pipe and a hose and collected in the main cleaning device unit. The debris enters a paper bag or the like and the air eliminated of debris is used to cool the motor drive section of the electric blower after which it is discharged outside through the exhaust opening. This can result in the discharged air blowing up dust that is present on the floor or carpet so that the dust is scattered all around the room.
Conventional technologies, e.g., Japanese examined utility model publication number 39-36553 and Japanese examined patent publication number 7-44911, have been developed in order to reduce the exhaust air blown out, improve debris collection, and the like. These technologies provide an electric cleaning device in which a hose, a pipe, and a suction tool connected to the main cleaning device unit are formed with an air intake path as well as a discharge path to allow the exhaust air to circulate.
However, in the conventional electric blower described above, the heat-generating motor drive section is cooled by taking all the exhaust air discharged radially by the centrifugal fan and redirecting it with the fan cover and the diffuser so that the air is passed through the bracket in which the motor drive section is mounted. This results in increased ventilation resistance, thus reducing suction properties.
Also, when the conventional electric blower described above is used in exhaust circulating cleaning devices described above, the cooling of the motor drive section results in a higher temperature for the exhaust air being circulated, leading to further increases in temperature. This increases the temperature of the main cleaning device unit, the hose, the pipe, and the motor itself. This can result in unpleasantness when using the cleaning device and may also invite deformation of the main cleaning device unit, as well as degradation or destruction of the motor or the like. Also, the contact between the carbon brush and the commutator of the motor generates carbon particles that enter the exhaust air cooling the motor drive section. When this air is circulated, carbon particles will adhere to the exhaust air path and can lead to the carbon particles being blown out from the suction tool and soiling the surface being cleaned. These factors acted as obstacles in the practical use of exhaust circulating cleaning devices.
In response to these problems, a separate fan can be attached to the motor shaft on the side opposite from the centrifugal fan (the rear side) in order to cool the motor drive section. Also, the paths of the exhaust air on the suction side and the exhaust air used for cooling are completely separated and a xe2x80x9cwet and dryxe2x80x9d motor is used to allow air containing moisture to be sucked in. However, with this arrangement, the cooling fan is attached separately, leading to a larger electric blower (and electric cleaning device). This results in a more complex structure, a significant reduction in ease of production, and increased costs.
It is an object of the present invention is to provide a blower for an electric cleaning device which overcome the problems described.
It is a further object of the invention to provide an electric blower having a simple structure that can improve suction properties.
Another object of the present invention is to prevent increases in temperature of circulating exhaust air in exhaust-circulation electric cleaning devices.
In order to achieve the objects described above, the present invention provides an electric blower wherein a diffuser is interposed between a centrifugal fan and a motor frame. A bracket in which a motor drive section is mounted is disposed downstream from the motor frame. The centrifugal fan and the diffuser are covered by a fan cover. Exhaust air discharged radially from the centrifugal fan is redirected to the motor drive section by the diffuser and the fan cover. The exhaust air passes from a ventilation opening of the motor frame through the bracket to cool the motor drive section. An exhaust opening is formed at a section of the fan cover. A portion of exhaust air discharged from the centrifugal fan is discharged from the exhaust opening of the fan cover.
The present invention can also have the exhaust opening formed at an outer perimeter section of the fan cover.
Furthermore, the present invention can also have a cooling fan disposed to cool the motor drive section.
Also, the present invention provides an electric cleaning device wherein an exhaust flow path and a suction flow path are formed in a hose, pipe, and suction tool connected to a main cleaning device unit in which is mounted an electric blower. The exhaust flow path circulates exhaust air from the electric blower. The electric blower described above is used so that exhaust air discharged from the exhaust opening of the fan cover is circulated to the exhaust flow path.
The present invention also provides an electric cleaning device wherein an exhaust flow path and a suction flow path are formed in a hose, pipe, and suction tool connected to a main cleaning device unit in which is mounted an electric blower. The exhaust flow path circulates exhaust air from the electric blower. The electric blower described above is used so that exhaust air discharged
The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.